Refracting luminous tube



May 17, 1932. L. HALL REFRACTING LUMINCUS TUBE Filed Nov. 15. 1929 file/1501.". lee fhlfi Patented May 17, 1932 PATENT o FicE LE HALL, OF CHICAGO, ILLDTOIS, ASSIGNOR TO CLAUDE NEON FEDERAL COMPANY,

01? CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE BEFBAC'I'ING LUMINOUS TUBE Application filed November 15, 1829. Serial No. 407,542.

invention relates to improvements in gaseous discharge or conductor tubes, as for mstance, of the Neon type, and has for 1ts principal object to provide an improved form and construction of such tubes wherein new and advantageous lighting effects are obtained, and particularly wherein the tube forms a self-contained optical system for projecting the light emitted from said tube in a beam of relatively intense hrilliancy.

As heretofore constructed, luminous discharge or conductor tubes have usually been made of cylindrical glass tubing, with the walls of the tube relatlvely thin and substantially uniformin thickness, so that the light stantially equal intensity in all directions.

In carrying out my invention, I provide an improved construction and arrangement of tube wherein the glass portion of the tube is made substantially thicker than heretofore, and the walls of said tube are formed in suitable shapes so as to utilize the refraction of light emitted at the enclosing surfaces to direct the rays emitted from the tube in in tcnsified beams of light. I also find it desirable in some instances to provide the rear,

portion of the tube with a suitable reflecting surface, which in conjunction with the re fracting surface at the front or open side of the tube produces increased effectiveness in directing the light rays in predetermined directions.

The invention maybest be understood by reference to the accompanying drawings, in which Figure 1 is a front view of a tube constructed in accordance with my invention.

Figure 2 is an enlarged horizontal section taken on line 22 of Figure 1.

Figure 3 is a horizontal section showing a modified form of tube in which the rear surface of the tube is provided with a reflecting medium.

Figure 4 is a fragmentary perspective view of a portion of the tubing of the form shown in Figure 3.

Figure 5' is a view of another form of tube somewhat similar to the form shown in the figlurcs illustrate certain various forms in ich th-einvention may be embodied. Figure 1 shows a front view of a tube 10 having electrodes 1111.of any suitable form enclosed atbpposite ends thereof. The body portion ,112 of said tube, instead of being generally cir is emitted radially from the tube with subcular and relatively thin in cross section, is substantially thicker than heretofore, and. is drawn with its side walls irregular in transverse section so as to produce refraction v of the emitted light on certain of its exterior surfaces. In the form shown in Fig ure 2, the glass body 12 is provided with a relatively small centrally disposed bore 13 in which the rarefied gas or other light source is contained. The side walls are flattened along two converging faces 14-14= while the opposite side wall 15 of the tube is substantially semi-circular.

With a tube of the shape shown in Figure 2, the light will be transmitted through the semi-circular surface of the tube in normal radial lines, but the light transmitted through the flattened surfaces 14-14 will be refracted generally toward an axial line formed by the central angle of the two converging faces I l-14. The light will therefore be transmitted in theform of a concentrated beam, and the tube, when viewed from the front of, or in line with the axis of the optical system thus produced, will be considerably brighter than when viewed from any other angle.

It will be understood that the angle of the refracting surfaces may be varied to obtain the desired width or angle of refraction of the emitted beam. In Figures 3 and 4 a modified form is shown in which the refracting surfaces l ke-14a are more clearly defined andarranged at a sharper angle than in the form shown in Figure 2, so that the concentrated beam may be somewhat narrower,

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and the line of light, when viewed from a point adgacent the axis of the tube, may be somewhat more intense and sharply defined.

' In the form shown in Figure 3, I also provide provided, all of the rays are transmitted through the front surfaces law-44a with greatly enhanced brilliancy.

The form shown in Figure 5 is substantiall the same construction and arrangement as shown in Figure 3, excepting that the reflecting surface at the rear face of the tube compnses a layer of material blown directly in the glass,-which may, for instance,'consist of milk-white pigment of the form commonly used in the art. The remaining portions of the glass, however, are clear or transparent as in the form shown in Figure 3.

The modified form shown in Figure 6 is provided with a substantially flat open face 141) and a reflecting rear face 16?) generally parabolic in shape so as to provide a relatively wide beam extending the full width of the open face 145, but with the rays emitted in substantially parallel lines at right an les to the front face 14a of the tube.

fiefracting tubes of the character above described may be readily formed by the ordinary glass drawing operations, in which the shapeof the final tube section is-determined by the initial section of the glass before drawing.

One of the uses for a retracting tube constructed in accordance with the above descri tion is suggested in Figure l in which a tu 10 extends along the top of a show case 20 and is arranged so that the beam of light is directed upon the articles contained in said show case.

It will be understood, however, that my improved form of tubes is adapted for many other purposes. When used in connection with signals, as for instance, in connection with aeroplane beacons or railway crossing signals, the light from the tube is greatly intensified and directed in an elongated bear 1 so as to be far more efiective, and the welllrnown fog penetrating characteristics of luminous discharge tubes are greatly enhanced.

Tubes of this character may also be applied with great advantage to display signs, so that some of the characters may be rendered much more brilliant than heretofore, when viewed at predetermined angles. My improved "form or tube Ina-'7 aiso be applied to indirect lighting a, as for for lighting the interior 0 :uiildings or when "used in stage fioodlights or foot-lights, where is desired to direct the emitted from the tube in predetermined directions. The

forms of tube including an opaque mirrored rear surface, such as shown in Figures 3 to 6, inclusive, are particularly. advantageous for such purposes, since it is unnecessary to provide other reflectors or shields to conceal illuminated portions of the tube or tubes from view.

Although I have shown and described certain particular embodiments of my invention, it will be understood that I do not wish to be limited to the exact constructions shown and described herein, but that various changes and modifications may be made without departing from the spirit and scope of my invention, as defined in the appended claims.

I claim as my invention:

1. A luminous conductor tube, said tube having a tubular bore and having substantially thick walls surrounding said bore, said walls being formed on one side of varyin thickness to retract the light rays given 0 by the gas in said tube to direct the rays emitted from the tube in an intensified beam of light extending substantially the length of the tube.

2. A luminous conductor tube, said tube having a tubular bore and having substan tially thick walls surrounding said bore, said Walls being formed on one side of varying thickness to retract the light rays given off by the gas in said tube to direct the rays emitted from the tube in an intensified beam of light extending substantially the length of the tube, and reflecting means rovided on the wall of said tube opposite sai refracting side of the tube.

In testimony that I claim the foregoing as my invention, 1 aiiix my signature this 12th day of November, A. D. 1929.

LEE HALL. 

